反应详情

A mixture of methyl 5-hydroxy-2,6-dimethyl-3-oxo-2,3-dihydropyridazine-4-carboxylate (3.00 g, 15.1 mmol) and 6 N aqueous HCl (25 mL, 150 mmol) in dioxane (25 mL) was refluxed for 48 hours. The reaction mixture was cooled to room temperature and concentrated under reduced pressure to give the crude material that was diluted with EtOAc. The organic layer was washed with water and brine, dried over MgSO4, filtered, and concentrated under reduced pressure to give 0.74 g (35%) of the desired product. The aqueous layer was concentrated under reduced pressure. The resulting solid was diluted with water and EtOAc-THF. The organic layer was separated. The aqueous layer was extracted with EtOAc (2×). The combined organic layers were dried over MgSO4, filtered, and concentrated under reduced pressure to give 0.80 g (37%) of the additional desired product. A total of 1.54 g (72%) of the desired product was obtained, which was used directly without further purification.

1. temperaturewas refluxed for 48 hours
2. concentrationconcentrated under reduced pressure
3. customto give the crude material that
4. washThe organic layer was washed with water and brine
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure